Experts said Trump could boost trade relations with the U.K., but alienate others.

While Donald J. Trump’s shocking triumph in the U.S. presidential election is still sinking in, across the Atlantic, news of an upset led by discontented voters felt all too familiar.

Real estate experts in London said Americans can expect some economic and financial uncertainty similar to the chaos felt directly after the British vote to exit the European Union in June. But they differed over how a Trump presidency might affect luxury real estate markets in the long term, as Mr. Trump could improve trade with Britons while alienating other foreign investors.

Trump’s win “will bring a property industry leader into the White House for the first time in American history. Without a doubt a Trump presidency will be pro-property and pro-real estate,” said Peter Wetherell, chief executive of Wetherell and a leading London real estate broker.

He said he thinks Mr. Trump’s presidency will greatly benefit the luxury real estate markets in the U.S. and internationally.

“It shows just as we had with the Brexit vote in the U.K. that American voters also want a change of direction,” Mr. Wetherell said.

Already since Brexit, there’s been an uptick in American buyers in London’s Mayfair and West End neighborhoods thanks to a depreciated pound, he said. And as Britons turn away from Europe, a Trump presidency could mean strengthened trade relations with the U.S., opening “the electrifying possibility of new U.S. and U.K. trade deals,” said Mr. Wetherell.

“We are already seeing over the last four months an upturn in U.K. buyers looking at New York, Miami and L.A.,” he said.

Stock futures plunged Tuesday night on the news of Democratic nominee Hillary Clinton’s looming defeat, but a meltdown failed to materialize on Wednesday. The Dow Jones industrial average was up more than 250 points to close at 18,589.69. Both the Standard & Poor’s 500, closing at 2,163.26, and the Nasdaq, at 5,251.07, were up more than 1% higher.

Specifically, stocks that stand to benefit from Mr. Trump’s proposals for infrastructure spending saw impressive gains, such as Caterpillar, which was up 7.7%.

And rather than plunging like the British pound in the wake of Brexit, the dollar rose broadly against other currencies, including the euro and the yen, on Wednesday. The dollar weakened slightly against the pound.

If the greenback does eventually slip, a devalued dollar would not be all bad news for some international investors. The weakened dollar would effectively strengthen the British pound, Mr. Hersham said. “It would therefore certainly help with pound-based purchases in the U.S.,” he said, particularly in cheaper luxury areas like Miami, where price per square foot is less than $1,000.

But outside of trade relations with the U.K., the president-elect’s offensive comments on the campaign trail about various ethnic and religious minorities may dissuade foreign investors from other parts of the world, particularly the Middle East, from buying property in a Trump-led America, said Becky Fatemi, director at Rokstone in London.

In the run-up to the election, Mansion Global surveyed brokers, listing agents and other industry experts around the world and found that a wide majority thought Mrs. Clinton would have been more favorable for luxury real estate markets.

Overall, 83% of respondents said Mrs. Clinton was the best person for the luxury real estate industry, while 17% opted for Donald Trump. The experts noted that her experience would offer stability next to Mr. Trump’s “wild card” presidency.

“Her clear experience on the national and international level will provide the sense of certainty that the market needs,” wrote one respondent in the anonymous survey.

“Everyone will benefit by having a smart, strong experienced level-headed leader,” wrote another respondent in favor of Mrs. Clinton.

Ms. Fatemi and several other agents told us they had expected Wednesday to be slow as people took time to soak in the news of Mr. Trump’s unpredicted win. Instead, it was business as usual for the residential market in prime central London, perhaps even busier than usual, Ms. Fatemi said.

“Because of Brexit, we’ve been slightly trained in swallowing that pill, digesting it, getting a bit of indigestion and moving on,” she said. “Prior to this, we had uncertainty, now we have clarity.”

It may take longer for real estate markets in U.S. cities to digest the news, said Jonathan Miller, president and CEO of appraisal firm Miller Samuel. But ultimately, Mr. Trump’s presidency shouldn’t have too much affect on prime areas like New York, and renewed pressure to keep interest rates low may even spur activity, he said.

“With the continuation of near record-low interest rates, I don’t see the election results as having much of an impact to the U.S. housing market after the short-term jitters pass,” Mr. Miller said.

Some said that there’s nothing to do but wait and see. If anything, Mr. Trump’s win signals that America and Britain with its Brexit vote are only the first in a groundswell of political defiance of large trade blocs, said James Roberts chief economist at Frank Knight. Germany, the Netherlands or France could be next when these countries hold elections next year, he said.

“The high level of volatility we have seen in global investment markets this year is set to continue,” Mr. Roberts said, “not just because of Trump, but also out of concern as to which major economy will be next to deliver a bombshell election result.”